You try to read data from a broken RAID. And your main problem is performance?

Yes. Well, no. I mean, I was just wondering... but what if the raid array was some many terabytes in size? It could take some days to rescue it. Just a few days spared could come in handy :)

I think you should not use perl for the job. There are better tools, and you seem to know none of them, including Perl

Come on, now you're being unfair. I am no perl developer, for sure, but I know a little. And if I'm here to ask, it's for sure because I don't know everything... why is there a "seekers of Perl wisdom" section at all, otherwise? It's not "guru meditations", afaik.
As for the "better tools", I would really like to know more, if you're willing to tell me.

Pay an expert to recover your RAID

Why? I did it myself. Using Perl, among other things. I'm enough an expert to get data back from a corrupted disk, raid array or whatever is still willing to give me some bit of information :)